Use of simulators in operative dental education: experience in southern Nigeria

Background: Though the use of simulators in operative dentistry is not new, the teaching and learning practices that take place during clinical sessions in skills laboratories are rarely reported. This study was designed to determine the current practices relating to teaching and learning of dental clinical skills in southern Nigeria.Methods: A cross-sectional study was conducted among the final year dental students in southern Nigeria using anonymous structured questionnaire as instrument for data collection. The questionnaire items included statements relating to existing teaching and learning practices. A five-point Likert scale response option was provided and descriptive summary statistics was computed.Results: There were 56 (34.8%) females and 105 (65.2%) males. Most of the students (41.0%) agreed that the theoretical concept behind clinical skills is taught prior to clinical sessions and most agreed that the objectives of each clinical session are stated and that the procedures are usually demonstrated. Most of the respondents (39.8%) agreed that feedback was sometimes embarrassing and given at the end of clinical sessions (76.6%). Equipment breakdown was a major challenge to learning.Conclusion: Dental education in the skills labs within the region appeared standard. However, feedback should be continuous and constructive. Equipment breakdown was the major constraint to learning.Key words: Simulators, Dentistry, Clinical skills laboratories, Dentistry, Simulator

Toxicity of powder and extracts of Zanthoxylum zanthoxyloides Lam (Rutaceae) root bark from Nigeria to three storage beetles

The root of Zanthoxylum zanthoxyloides Lam is used as antibacterial toothbrush in southwestern Nigeria. The root bark was therefore screened as powder, aqueous and ethanolic extracts for toxicity to adult Callosobruchus maculatus F. (Coleoptera: Bruchidae), Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the effects of the test extracts on oviposition and progeny development of C. maculatus in laboratory tests. A small scale field trial was also carried out to test the efficacy of test powder as a protectant of cowpea, Vigna unguiculata (L.) Walpers and maize, Zea mays L. grains against insect infestation. Results of the acute toxicity tests showed that all the formulations were toxic to the insects. The 48 h median lethal concentration (LC50) values obtained for the test powder against C. maculatus, S. zeamais and T. castaneum are 0.05 g kg-1, 0.01g kg-1 and 0.04 g kg-1, respectively. For the aqueous extracts the LC50 values are 0.83 g L-1, 0.34 g L-1 and 0.38 g L-1 against C. maculatus, S. zeamais and T. castaneum, respectively while the values are 0.02 g L-1, 0.04 g L-1 and 0.09 g L-1, respectively for ethanolic extract, indicating higher toxicity against the test insects relative to the water-based extract. The ethanolic extract demonstrated residual property, the toxicity to C. maculatus remaining fairly constant over a total post-treatment time of 336 h. Cowpea grain treatment with test plant ethanolic extract resulted in reduction of the number of eggs laid from 93.30 ± 3.46 in the control to 21.00 ± 4.57 in grain treated with 0.10 g L-1 extract without significant difference in the number of adult emergence from the treated grains. Field trials showed that cowpea and maize grains treated with test plant powder respectively were protected from insect infestation for 180 d. These results demonstrate the potentials of Z. zanthoxyloides for protecting cowpea and maize grains against storage insects.Keywords: Zanthoxylum zanthoxyloides, Callosobruchus maculatus, Sitophilus zeamais, Tribolium castaneum, Toxicit

Topside Pipeline Design for Slug Attenuation and Increased Oil Production

In oil and gas production system, slugging is frequently encountered when gas-liquid mixtures are transported through a common pipeline-riser system. This phenomenon usually manifests in significant fluctuation of flow and pressure which can impact the production system negatively. Topside choking is usually employed as a mitigation technique but with its attendant reduction in production capacity. The objective of this study therefore is to investigate the optimisation of topside pipeline diameter and choking for effective slug attenuation and optimised oil production. In this paper, a new method for slug flow attenuation has been proposed. The potential of using effective topside pipeline- diameter design for slug flow attenuation was theoretically shown. Numerical studies were also done to show that the concept can indeed be adapted for effective slug attenuation using an industrial software. Experimental studies were conducted in a 4” pipeline -riser system to validate the numerical and theoretical studies. The results showed that the optimised design of topside pipe diameter has potential for slug flow attenuation at larger valve opening which effectively translates to lower pressure and increased oil production. For the case studied, up to 49% reduction in the pressure drop across the topside choke valve was reported which practically implied increased flow capacity. An optimum volume which satisfied size, system stability and production constraints was obtained

Experimental Investigation of Hydrodynamic Slug Flow in Pipeline-Riser Systems

Activities in oil and gas industry have shifted deep offshore. There is therefore the need to envisage and accurately provide for flow assurance challenges that might be encountered throughout the life of a field. Slug flow is one of the flow assurance concerns confronting the industry. The objective of the study was to gain insight into the behaviour of hydrodynamic slug flow in pipeline-riser system. This understanding is needed for the development of appropriate slug control strategy. Experimental studi es were conducted in a 2” pipeline-riser system and a 2” horizontal two -phase flow facility. Slug envelopes were developed for the pipeline-riser system, the vertical and the horizontal pipes. The results revealed three distinct slug flow behaviours. The first type of slug was formed in the horizontal pipeline and transported through the riser pipe nearly unchanged, the second type of slugs were formed in the horizontal pipe but also experience growth in the riser pipe while the third are slugs formed in the vertical pipe without the influence of the upstream horizontal pipe. There is therefore the need to develop appropriate slug control strategies based on the observed behaviour of the identified region

Aflatoxins in Nigerian Groundnut: Continuous Threat to Health, Agriculture and Foreign Trade, Policy Brief 35

Groundnut is the most common host of aflatoxin world wide. In Nigeria, this crop is largely grown by resource-limited farmers under rainfed conditions. Most of the groundnut and groundnut-based products grown and/or sold in Nigeria contain varying quantities of aflatoxins. At least 30% of groundnut grains and seeds sold on local markets are contaminated by aflatoxins, with 25-83% of them exceeding permissible levels for many countries, including Nigeria. Aflatoxin contaminations are higher in local groundnut varieties than in improved ones. Similarly, 87-100% of kuli kuli consumed in Nigeria is contaminated by aflatoxins; the situation of many other groundnut-based products are not very different from that of kuli kuli. This Policy Brief is an integral component of proactive measures being taken to create awareness and sustain on going measures to effectively manage aflatoxin contamination in groundnut and other crops prone to aflatoxin contamination. Other measures include regular use of good agricultural practices, consistent enforcement of pertinent existing, and constant re-assessment and revision of policies, regulations and evolving biological control methods

Bioactivity of Powder and Extracts from Garlic, Allium sativum L. (Alliaceae) and Spring Onion, Allium fistulosum L. (Alliaceae) against Callosobruchus maculatus F. (Coleoptera: Bruchidae) on Cowpea, Vigna unguiculata (L.) Walp (Leguminosae) Seeds

Laboratory bioassays were conducted to investigate the bioactivity of powders, extracts, and essential oils from Allium sativum L. (Alliaceae) and A. fistulosum L. (Liliaceae) against adults, eggs, and larvae of Callosobruchus maculatus F. (Coleoptera: Bruchidae). On the basis of 48 hr median lethal toxicity (LC50), test plant powders and extracts from A. sativum were more toxic to C. maculatus adults than those from A. fistulosum. The 48 hr LC50 values for the powder against the test insect species were 9.66 g/kg and 26.29 g/kg for A. sativum and A. fistulosum, respectively. Also the 48 hr LC50 values obtained show that aqueous extracts of the test plant species, 0.11 g/L (A. sativum) and 0.411 g/L (A. fistulosum) were more toxic to C. maculatus than the corresponding ethanol extracts. There was no significant difference in the toxicity of vapours from the two test plant species against C. maculatus, although A. sativum gave lower values. The study shows that A. sativum and A. fistulosum have potentials for protecting stored cowpea from damage by C. maculatus

Full Length Research Article - THE EFFECT OF MOTHERS PAST DENTAL EXPERIENCE ON THE BEHAVIOUR OF SOME NIGERIAN CHILDREN DURING DENTAL TREATMENT

The objective of this study was to assess the effect of the mother’s past dental experience on the behaviour of some Nigerian children during dental treatment. Two hundred and sixty children aged 3 – 15 years participated in this study. They were treated at the three government dental establishments in Ibadan, a city in southwestern Nigeria, over a six-month period. The children’s behaviour during different stages of treatment were determined by the Frankl’s Behaviour Rating Scale. The outcome of the study revealed that the mother’s past dental experiences were found to influence the children’s behaviour at the initial steps of treatment. On entering the operatory, 92.5% of the children whose mothers had pleasant memories of their dental experiences reacted positively in comparison to 60% who had mothers with previous traumatic experiences (p<0.05). During examination, 92.5% of children whose mothers enjoyed dental treatment in the past complied, while 68.0% who had mothers with past negative experiences were cooperative (p<0.05). Behaviour of children at latter stages of treatment revealed a tendency towards improved behaviour where the mothers past dental experiences had been pleasurable. From this study, it has been established that enquiring into the mother’s past dental experience, among other things, is important for successful child dental care. Even though it was significant only at the preliminary stages of treatment, it would appear that these stages are the most critical in gaining the childs confidence and getting him accustomed to the clinic environment. In circumstances where mother’s past dental experience has been negative, the dentist will need to educate, counsel and allay the fears, which may have persisted in such parents for years. This will help reassure the parents as the mothers cooperation will be needed in order to provide the children with the best dental care. Where the mothers’ unpleasant dental experiences had influenced the childs behaviour negatively, efforts should be geared towards instituting appropriate behaviour management skills in these children in order to bring about a higher level of compliance during dental visits

Knowledge and attitude of some Nigerian dentists concerning the use of space maintainers in Dentistry

Objective: This study was carried out to determine the knowledge and attitude of some Nigerian dentist concerning the use of space maintainers in dentistry. Method: Structured and self administered questionnaires were sent to 60 dentists in Ibadan and Ile -Ife towns in the South - West region of Nigeria. Information required include respondent\\u27s biodata, year of graduation, specialty, knowledge of space maintainer, how often it is recommended, reasons for not recommending, and the types usually recommended. Result: Forty Six (70.6%) dentists comprising 63% females and 37% males responded to the questionnaire. All respondents were familiar with space maintainers but 28 (60.8%) claimed that they had never recommended it before. A number of reasons were given for not recommending space maintainers Fifty percent (50%) of those who had never recommended claimed that there was no orthodontic technician to fabricate it and that it was an expensive procedure, 39.2% claimed it was due to lack of appropriate dental materials needed for its fabrication, 7.1% claimed that the children may not cooperate and 7.1% claimed that parents did not want it for their children. The commonest space maintainer used by the dentists was the removable partial denture (71.8%) followed by Band and Loop (28.2%). None used lingual arch and distal shoe. Conclusion: The most commonly used space maintainer in this environment is the removable partial denture. All 46 dentists agreed that space maintainers help in preventing malocclusion and subsequently agreed to recommend space maintainers if the required materials were available and whenever it was necessary to do so